Schizophrenia is a chronic disorder, usually necessitating lifelong treatment. Although atypical antipsychotic agents have improved outcomes in schizophrenia, their clinical potential remains limited by patients' nonadherence to medication. Long-acting antipsychotics were developed in the 1960s to enhance treatment adherence and simplify the medication process. However, although conventional long-acting agents assure medication delivery, they are associated with similar side effects to their oral equivalents. The need for an agent combining the advantages of a long-acting formulation with those of an atypical antipsychotic was highlighted in 1997 by the American Psychiatric Association's Practice Guideline for the Treatment of Patients with Schizophrenia. The first long-acting injectable atypical antipsychotic, long-acting risperidone (Risperdal Consta, Johnson & Johnson), has since been developed. This article discusses the efficacy, tolerability and cost-effectiveness of long-acting risperidone in schizophrenia and bipolar disorder patients, and suggests possibilities for how its role in clinical practice may change over the next 5 years.